Acrylonitrile polymers stabilized with certain hydroxymethyl formamides and acetamides



Patented June 15, 195 4 3 UNITED STATES PATENT OFFICE ACRYLONITRILE POLYMERS STABILIZED WITH CERTAIN HYDROXYMETHYL FORMAMIDES AND ACETAMIDES George W. Stanton and Forrest A. Eh'lers, Walnut Creek, Califi, assignors to The Dow Chemical Company, Midland, Mich., a corporation of Delaware NoDrawing. Application September 4, 1952, Serial No. 307,914

7 Claims. (Cl. 26045.9=)

This invention relates to compo i s o ma turntable, with half of the film covered and the t r consisting s tial y of a p ym r ontainother half exposed. The turntable was set in s at least 60 per cent of acrylon ile in th motion in a Fadeometer, and the exposed films p ym m e ul nd a stabilizing agent t p were irradiated .for 12c hours. The several films t he p ym r from the embrittling or diswere then tested with a photoelectric reflection Coloring effects of p u t ght or heat. meter which had been set to read 100 when Polyacrylonitrile and copolymers containing turned toward a glazed white tile (see footnote). acrylonitrile as the predominant constituent An exposed but untreated film of the copolymer nd r nd irabl physical changes up n p gave readings of about 70 and had a light tan longed exposure to light or to heat. The obcolor, while the covered and unexposed portions servable symptoms of such changes are embrittleof all the films gave readings of 90 to 96, using ment or discoloration, or both, due, in varying the white tile standard as a background. measure to the action of either light or heat. Results with typical compounds in the recited Since the uses to which such polymers are put class are given below:

include the manufacture of molded articles and 15 thin films, either embrittlement or discoloration Reflection meter read- 18 to be avoided, if possible. To th s end, it would Test Compound mg ammo hrs. in be desirable to provide agents which can be ad- Fadeometer mixed with the polymers to protect them against one or more of the adverse effects of the condi- 20 (Stalzllizers): b No tions to which they may be exposed. The proifgsmggggga;532555155 ?fella v i sof vision of stabilized compositions of the polymers amide. and such protective agents is the principal object -ggggf of the present invention. N,N-di-(2-hydroxyethyDformamide Do. This object is realized, according to the invenh s e oxyethy1 N-meth 1 acet- Do. tion, by mixing with the polymer from 2 to 20, N- a yoroxyetn nN-eth i acet- Do. and preferably from 5 to 15 per cent by weight of N,alidfzz hydmxyethynacetamide a compound having the general formula For contrast (non-stabilizers):

N-2-11ydroxyethyl iormamlde about 71, very brittle. X N-2-hydroxyethy1acetamide opaque and very" brittle. N -2-hydroxy-hexaetlioxyethyl acetunder 71, very brittle.

N-C=O amide. HO CzHl Y wherein X is methyl, ethyl P h and To determine the effective concentration of Y 15 methyl hydrogffn; The tab lhzersi then, stabilizer in the acrylonitrile copolymer, a series are alkyl or hydroxyetnyl substitution products f films was made with Varying amounts of 01. hydroxyethyl formamide or acetam de. Art1- (2 hydroXyethy1)N methy1 f mamid and the @165 made from the um Composltlons Show films were exposed as before for 120 hours in the little or no tendency to discolor upon prolonged Fadeometen exposure to ultraviolet light, and exhibit little of the tendency to become brittle as a result of 40 such exposure, especially when the stabilizer is percent by weight N-(2-hydroxyethyl)N-methyl 3333 present at concentrations of 5 per cent or more. fermamide reading A copolymer of 80 per cent acrylonitrile and 20 per cent isobutylene was prepared in aqueous None about 70. emulsion, the polymeric particles were coagulated 15 6 51315 71. by addition of magnesium chloride solution, and 412:: t the coagulum was washed and dried. This 00- about85.

11. polymer was found to be soluble to the extent of 15.0 Do. over 15 per cent by weight in acetone. In evaluating the various stabilizers, a 15 per cent solu- NOTE the Fadeometer employed two type SP4 111 11 of h copolymer 1n acetone s prepared, General Electric Sunlight lamps are disposed horizontally an nt f tabilizer qual t 15 per nt of and parallel to one another, with the centers of the bulbs h Weight of cflpolymel Was dissolved in the placed 6 inches from the center of a IZ-inch'turntable Solution, and films were t f o t Solution on driven at 33% revolutions per minute. The reflection lass p at Th fi s w dr d n a r v rration Madison Ave, New York city, having a trinight, t t 70 C f r one h h lti stimulus blue filter and set to read when turned toward a color-standard white ceramic Vitrolite tile supplied by films were mounted near the rim of a horizontal G d Laboratories, Bethesda, Md.

The samples containing 5 per cent or more of the stabilizer were non-brittle, or much less brittle than those containing smaller amounts of stabilizer. The same stabilizer was added in amounts from 5 to 15 per cent by weight to various polymeric bodies in which acrylonitrile was the predominant polymerized constituent, and the products were exposed in a Fadeometer and tested with the reflection meter, with the following results. The products tested were fibers, films or flow moldings.

Polymer Composition gala ggg Polyacrylonitrila (fiber) 454 about 90. Acrylonltrile80%; Isobutylene20% 120 over 89. Acrylonltrlle60%; Methyl acry1ate40%...... 166 Do.

HO C1114 Y wherein X is selected from the group consisting of methyl, ethyl and 2-hydroxyethyl and Y is from the group consisting of methyl and hydrogen.

2. The composition claimed in claim 1, wherein the stabilizer is present in amount from 5 to 15 per cent of the Weight of polymer.

3. The composition claimed in claim 1, wherein the stabilizing agent is N-(2-hydroxyethyDN- methyl formamide.

4. The composition claimed in claim 1, wherein the stabilizing agent is N-(Z-hydroxyethyDN- methyl acetamide.

5. The composition claimed in claim 1, wherein the stabilizing agent is N-(2-hydroxyethyDN- ethyl formamide.

6. The composition claimed in claim 1, wherein the stabilizing agent is N- (2-hydroxethyl) N-ethyl acetamide.

7. The composition claimed in claim 1, wherein the stabilizing agent is N,N-di-(2-hydroxyethyl) formamide.

No references cited. 

1. A COMPOSITION OF MATTER THE ESSENTIAL CONSTITUENTS OF WHICH ARE A POLYMERIC BODY CONTAINING AT LEAST 60 PER CENT BY WEIGHT OF ACRYLONITRILE POLYMERIZED IN THE POLYMER MOLECULE, ANY BALANCE BEING ANOTHER MONOETHYLENICALLY UNSATURATED COMPOUND COPOLYMERIZED WITH ACRYLONITRILE, AND, AS A STABILIZING AGENT THEREFOR, FROM 2 TO 20 PER CENT BY WEIGHT OF A COMPOUND HAVING THE GENERAL FORMULA 